Electric 22mm pipe soldering tool - any good?

[Nightjar]

[Phil Addison]

[Phil Addison]

Indeed, but very easily. Is there a definition of accessible?

Yes, at least I think that's what is causing the faint smell - it could be a dead rat though; next door had the ratcatcher in a while back to clear them out from under their front porch. My under floor space is well ventilated and it seems to be a very small leak - I've turned off everything and the meter dial didn't budge overnight, though I realise that's not a very sensitive test.

I really want to do a better leak test before I embark on this, but I have to get down there anyway to properly clip up the pipe. I was thinking of a water gauge to look for falling pressure, or is it necessary to pump it up to a higher pressure first?

Soldering with no flux? As I'm hoping it only needs re-flowing that's probably ok, but I didn't think fluxless copper to copper soldering was realistic, thats certainly my experience, or do you mean there is a non-acid flux that can be used? What's the problem with acid flux anyway?

Phil

[Clive George]

[Nightjar]

[Roger Mills]

You should be able to test it ok at normal gas pressure. I have a feeling that a certain drop in pressure is acceptable - but you'd need to look up the rules.

I would start by getting a can of spray-on leak detector. If you surround each joint with foam, you'll see bubbles if there are any leaks.

Now that we know they're gas pipes, I'll retract my push-fit suggestion. It would have saved time if you'd said so at the outset.

[Phil Addison]

I've got a water gauge on it now. The initial pressure was 25cms of water, and over the last 2.5 hours its been dropping at about 2.5 cms/hour from a volume of pipework which I estimate to be about 40 litres.

Having measured a leak rate I'm fairly convinced it needs sorting out but I'm surprised how small it is. Would you expect this size of leak to be responsible for a vague and intermittent spell of (possibly*) gas in the house, given the pipework is in a fairly** well ventilated crawl space under the floor?

• We are not even sure it IS a gas smell!

** 3x 9"x6" airbricks at the front, 2x 9"x6" and 3x 9"x3" airbricks at various locations at the back.

Yes indeed, sorry about that, mae culpa! All I can say is I was initially concentrating on a tool for reflowing existing joints, it hadn't occurred to me to replace them.

Phil

[Ron Lowe]

Here at Lowe Towers, under my suspended floor, the copper pipework is suspended from the joists by off-cuts of 2.5 T+E nailed to each side of the joist, providing a loop or cradle. It's still perfectly serviceable, and I'd guess it was installed back in the '70s.

Presumably zero cost to the plumber who installed it at the same time the sparky was leaving off-cuts around.

Makes a change from the plumber nailing the live T+E, I suppose.

[Phil Addison]

Now that IS a good idea, easy to fit, easily adjustable height, no worries about any pipe expansion, cheap, and readily to hand too. The last point alone makes it a winner for me!!

Sits back and waits to hear the downside... ;)

One for the handy tips file?

Phil

[Appelation Controlee]

The perfumant added to gas is intended to get your attention in very small concentrations.

[Skipweasel]

"Perfumant" is a bit decorative, isn't it? "Stench" would seem nearer the mark.

[John Williamson]

I think the Gas Board called it an odourant.

[Nick Leverton]

Good search tip ... "The gas odorant (sic) used in the UK today is a blend of mercaptan and sulphide" - thanks to Mr. Google. Though they don't say which mercaptan or which sulphide (not H2S as it is poisonous, I presume !). Methyl mercaptan used to have a (since surpassed) record for smelliest stuff, if I remember my old GBOR's correctly.

Nick

[Tim Watts]

Nick Leverton ( [e-mail]) wibbled on Monday 14 March 2011 23:50:

And H2S anaesthetises the olfactory receptors so the smell seems to dimunish even though concentrations remain level - would be a bit useless in this context.

[Phil Addison]

It certainly did that! Now with the gas main turned off we can still smell it. I think at least some of it is lingering in the carpets that it presumably percolated up through.

Any advice on how to do the leak test? I don't want to dive under the crawl space with the gas turned on and potentially leaking, and with it turned off the pressure will probably fall away before I've loacated the leak with bubbly detector foam. So I'm thinking of rigging a bicycle pump to flush the gas out and pressurise it with air instead, which can be kept topped up. Bear in mind the leak is under the floor so it will take quite a while to grovel around to find which joint/s is/are leaking. Is that a reasonable approach?

Phil

[Skipweasel]

IIRC they reduced the amount a few years ago as they were getting too many leaks reported - BICBW.

[GB]

Hot water pipes makes the insulation smell?

[Phil Addison]

Hmm no advice???

Anyway, I got the floorboards up today and guess what - a dead rat laying right under where the (faint) smell is strongest. But I've re-checked the leak rate today with proper manometer rather than my lash-up of plastic tube and string, and got pretty much the same leak - dropping 1-2 cms/hr.

Also made a nice air-pump adaptor to tee into the manometer line; 8mm microbore tee and football adaptor with integral Shrader valve, and bicycle pump, so I can pressure test tomorrow and try out my can of B&Q squirty stuff (Rothenberger).

So still not sure if I have a real leak or its just the dead rat, or his mates further away where I haven't looked yet. To be honest he didn't seem to pong much.

Phil

[Terry Casey]

This reminds me of the days when selenium rectifiers were common in TV sets.

They consisted of a number of rectifier elements on a rod, each having its own square heatsink. The problem was when one element broke down but the remainder were still capable of working with no discernible effect to the working of the TV.

The smell would be released very slowly and continue for a long time after the TV was switched off so that, with normal use, it was virtually continuous. This, coupled with the slow release which enabled the smell to permeate throughout the entire room, the TV rarely came under suspicion.

The smell was vile and, to the uninitiated, completely unrecognisable but with sufficient similarities to other noxious odours to cause lots of confusion.

Eventually the recifier would fail completely or, quite commonly, some other fault might develop. Enter the repairman, who only needed one whiff[1] to identify the source ...

Someone documented some of the mistaken causes of the smell once. These included calls to the gas board to investigate gas leaks which, of course, didn't exist, local councils sending in the rat catcher and, in one house at least, the dog had been singled out as the culprit!

[1] No training required beyond fitting one of these devices. They always succeeded in emitting a couple of little whiffs as you soldered the connecting wires ...

[tony sayer]

Jeezz!, didn't they stink. Used to wire a silicon diode across them with a series limiter resistor. Mind you a long time ago now;!..

Used to do that on some olde valve sets the guvnor either reckoned it was cheaper of we couldn't get the right valves anymore;!